src/nspawn/nspawn.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2010 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <signal.h>
  23 #include <sched.h>
  24 #include <unistd.h>
  25 #include <sys/types.h>
  26 #include <sys/syscall.h>
  27 #include <sys/mount.h>
  28 #include <sys/wait.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31 #include <stdio.h>
  32 #include <errno.h>
  33 #include <sys/prctl.h>
  34 #include <sys/capability.h>
  35 #include <getopt.h>
  36 #include <sys/poll.h>
  37 #include <sys/epoll.h>
  38 #include <termios.h>
  39 #include <sys/signalfd.h>
  40 #include <grp.h>
  41 #include <linux/fs.h>
  42 #include <sys/un.h>
  43 #include <sys/socket.h>
  44 #include <linux/netlink.h>
  45
  46 #include <systemd/sd-daemon.h>
  47 #include <systemd/sd-bus.h>
  48
  49 #include "log.h"
  50 #include "util.h"
  51 #include "mkdir.h"
  52 #include "macro.h"
  53 #include "audit.h"
  54 #include "missing.h"
  55 #include "cgroup-util.h"
  56 #include "strv.h"
  57 #include "path-util.h"
  58 #include "loopback-setup.h"
  59 #include "sd-id128.h"
  60 #include "dev-setup.h"
  61 #include "fdset.h"
  62 #include "build.h"
  63 #include "fileio.h"
  64 #include "bus-util.h"
  65 #include "ptyfwd.h"
  66
  67 #ifndef TTY_GID
  68 #define TTY_GID 5
  69 #endif
  70
  71 typedef enum LinkJournal {
  72         LINK_NO,
  73         LINK_AUTO,
  74         LINK_HOST,
  75         LINK_GUEST
  76 } LinkJournal;
  77
  78 static char *arg_directory = NULL;
  79 static char *arg_user = NULL;
  80 static sd_id128_t arg_uuid = {};
  81 static char *arg_machine = NULL;
  82 static const char *arg_slice = NULL;
  83 static bool arg_private_network = false;
  84 static bool arg_read_only = false;
  85 static bool arg_boot = false;
  86 static LinkJournal arg_link_journal = LINK_AUTO;
  87 static uint64_t arg_retain =
  88         (1ULL << CAP_CHOWN) |
  89         (1ULL << CAP_DAC_OVERRIDE) |
  90         (1ULL << CAP_DAC_READ_SEARCH) |
  91         (1ULL << CAP_FOWNER) |
  92         (1ULL << CAP_FSETID) |
  93         (1ULL << CAP_IPC_OWNER) |
  94         (1ULL << CAP_KILL) |
  95         (1ULL << CAP_LEASE) |
  96         (1ULL << CAP_LINUX_IMMUTABLE) |
  97         (1ULL << CAP_NET_BIND_SERVICE) |
  98         (1ULL << CAP_NET_BROADCAST) |
  99         (1ULL << CAP_NET_RAW) |
 100         (1ULL << CAP_SETGID) |
 101         (1ULL << CAP_SETFCAP) |
 102         (1ULL << CAP_SETPCAP) |
 103         (1ULL << CAP_SETUID) |
 104         (1ULL << CAP_SYS_ADMIN) |
 105         (1ULL << CAP_SYS_CHROOT) |
 106         (1ULL << CAP_SYS_NICE) |
 107         (1ULL << CAP_SYS_PTRACE) |
 108         (1ULL << CAP_SYS_TTY_CONFIG) |
 109         (1ULL << CAP_SYS_RESOURCE) |
 110         (1ULL << CAP_SYS_BOOT) |
 111         (1ULL << CAP_AUDIT_WRITE) |
 112         (1ULL << CAP_AUDIT_CONTROL);
 113 static char **arg_bind = NULL;
 114 static char **arg_bind_ro = NULL;
 115
 116 static int help(void) {
 117
 118         printf("%s [OPTIONS...] [PATH] [ARGUMENTS...]\n\n"
 119                "Spawn a minimal namespace container for debugging, testing and building.\n\n"
 120                "  -h --help                Show this help\n"
 121                "     --version             Print version string\n"
 122                "  -D --directory=NAME      Root directory for the container\n"
 123                "  -b --boot                Boot up full system (i.e. invoke init)\n"
 124                "  -u --user=USER           Run the command under specified user or uid\n"
 125                "     --uuid=UUID           Set a specific machine UUID for the container\n"
 126                "  -M --machine=NAME        Set the machine name for the container\n"
 127                "  -S --slice=SLICE         Place the container in the specified slice\n"
 128                "     --private-network     Disable network in container\n"
 129                "     --read-only           Mount the root directory read-only\n"
 130                "     --capability=CAP      In addition to the default, retain specified\n"
 131                "                           capability\n"
 132                "     --link-journal=MODE   Link up guest journal, one of no, auto, guest, host\n"
 133                "  -j                       Equivalent to --link-journal=host\n"
 134                "     --bind=PATH[:PATH]    Bind mount a file or directory from the host into\n"
 135                "                           the container\n"
 136                "     --bind-ro=PATH[:PATH] Similar, but creates a read-only bind mount\n",
 137                program_invocation_short_name);
 138
 139         return 0;
 140 }
 141
 142 static int parse_argv(int argc, char *argv[]) {
 143
 144         enum {
 145                 ARG_VERSION = 0x100,
 146                 ARG_PRIVATE_NETWORK,
 147                 ARG_UUID,
 148                 ARG_READ_ONLY,
 149                 ARG_CAPABILITY,
 150                 ARG_LINK_JOURNAL,
 151                 ARG_BIND,
 152                 ARG_BIND_RO
 153         };
 154
 155         static const struct option options[] = {
 156                 { "help",            no_argument,       NULL, 'h'                 },
 157                 { "version",         no_argument,       NULL, ARG_VERSION         },
 158                 { "directory",       required_argument, NULL, 'D'                 },
 159                 { "user",            required_argument, NULL, 'u'                 },
 160                 { "private-network", no_argument,       NULL, ARG_PRIVATE_NETWORK },
 161                 { "boot",            no_argument,       NULL, 'b'                 },
 162                 { "uuid",            required_argument, NULL, ARG_UUID            },
 163                 { "read-only",       no_argument,       NULL, ARG_READ_ONLY       },
 164                 { "capability",      required_argument, NULL, ARG_CAPABILITY      },
 165                 { "link-journal",    required_argument, NULL, ARG_LINK_JOURNAL    },
 166                 { "bind",            required_argument, NULL, ARG_BIND            },
 167                 { "bind-ro",         required_argument, NULL, ARG_BIND_RO         },
 168                 { "machine",         required_argument, NULL, 'M'                 },
 169                 { "slice",           required_argument, NULL, 'S'                 },
 170                 { NULL,              0,                 NULL, 0                   }
 171         };
 172
 173         int c, r;
 174
 175         assert(argc >= 0);
 176         assert(argv);
 177
 178         while ((c = getopt_long(argc, argv, "+hD:u:bM:jS:", options, NULL)) >= 0) {
 179
 180                 switch (c) {
 181
 182                 case 'h':
 183                         help();
 184                         return 0;
 185
 186                 case ARG_VERSION:
 187                         puts(PACKAGE_STRING);
 188                         puts(SYSTEMD_FEATURES);
 189                         return 0;
 190
 191                 case 'D':
 192                         free(arg_directory);
 193                         arg_directory = canonicalize_file_name(optarg);
 194                         if (!arg_directory) {
 195                                 log_error("Failed to canonicalize root directory.");
 196                                 return -ENOMEM;
 197                         }
 198
 199                         break;
 200
 201                 case 'u':
 202                         free(arg_user);
 203                         arg_user = strdup(optarg);
 204                         if (!arg_user)
 205                                 return log_oom();
 206
 207                         break;
 208
 209                 case ARG_PRIVATE_NETWORK:
 210                         arg_private_network = true;
 211                         break;
 212
 213                 case 'b':
 214                         arg_boot = true;
 215                         break;
 216
 217                 case ARG_UUID:
 218                         r = sd_id128_from_string(optarg, &arg_uuid);
 219                         if (r < 0) {
 220                                 log_error("Invalid UUID: %s", optarg);
 221                                 return r;
 222                         }
 223                         break;
 224
 225                 case 'S':
 226                         arg_slice = strdup(optarg);
 227                         break;
 228
 229                 case 'M':
 230                         if (!hostname_is_valid(optarg)) {
 231                                 log_error("Invalid machine name: %s", optarg);
 232                                 return -EINVAL;
 233                         }
 234
 235                         free(arg_machine);
 236                         arg_machine = strdup(optarg);
 237                         if (!arg_machine)
 238                                 return log_oom();
 239
 240                         break;
 241
 242                 case ARG_READ_ONLY:
 243                         arg_read_only = true;
 244                         break;
 245
 246                 case ARG_CAPABILITY: {
 247                         char *state, *word;
 248                         size_t length;
 249
 250                         FOREACH_WORD_SEPARATOR(word, length, optarg, ",", state) {
 251                                 cap_value_t cap;
 252                                 char *t;
 253
 254                                 t = strndup(word, length);
 255                                 if (!t)
 256                                         return log_oom();
 257
 258                                 if (cap_from_name(t, &cap) < 0) {
 259                                         log_error("Failed to parse capability %s.", t);
 260                                         free(t);
 261                                         return -EINVAL;
 262                                 }
 263
 264                                 free(t);
 265                                 arg_retain |= 1ULL << (uint64_t) cap;
 266                         }
 267
 268                         break;
 269                 }
 270
 271                 case 'j':
 272                         arg_link_journal = LINK_GUEST;
 273                         break;
 274
 275                 case ARG_LINK_JOURNAL:
 276                         if (streq(optarg, "auto"))
 277                                 arg_link_journal = LINK_AUTO;
 278                         else if (streq(optarg, "no"))
 279                                 arg_link_journal = LINK_NO;
 280                         else if (streq(optarg, "guest"))
 281                                 arg_link_journal = LINK_GUEST;
 282                         else if (streq(optarg, "host"))
 283                                 arg_link_journal = LINK_HOST;
 284                         else {
 285                                 log_error("Failed to parse link journal mode %s", optarg);
 286                                 return -EINVAL;
 287                         }
 288
 289                         break;
 290
 291                 case ARG_BIND:
 292                 case ARG_BIND_RO: {
 293                         _cleanup_free_ char *a = NULL, *b = NULL;
 294                         char *e;
 295                         char ***x;
 296
 297                         x = c == ARG_BIND ? &arg_bind : &arg_bind_ro;
 298
 299                         e = strchr(optarg, ':');
 300                         if (e) {
 301                                 a = strndup(optarg, e - optarg);
 302                                 b = strdup(e + 1);
 303                         } else {
 304                                 a = strdup(optarg);
 305                                 b = strdup(optarg);
 306                         }
 307
 308                         if (!a || !b)
 309                                 return log_oom();
 310
 311                         if (!path_is_absolute(a) || !path_is_absolute(b)) {
 312                                 log_error("Invalid bind mount specification: %s", optarg);
 313                                 return -EINVAL;
 314                         }
 315
 316                         r = strv_extend(x, a);
 317                         if (r < 0)
 318                                 return r;
 319
 320                         r = strv_extend(x, b);
 321                         if (r < 0)
 322                                 return r;
 323
 324                         break;
 325                 }
 326
 327                 case '?':
 328                         return -EINVAL;
 329
 330                 default:
 331                         log_error("Unknown option code %c", c);
 332                         return -EINVAL;
 333                 }
 334         }
 335
 336         return 1;
 337 }
 338
 339 static int mount_all(const char *dest) {
 340
 341         typedef struct MountPoint {
 342                 const char *what;
 343                 const char *where;
 344                 const char *type;
 345                 const char *options;
 346                 unsigned long flags;
 347                 bool fatal;
 348         } MountPoint;
 349
 350         static const MountPoint mount_table[] = {
 351                 { "proc",      "/proc",     "proc",  NULL,       MS_NOSUID|MS_NOEXEC|MS_NODEV, true  },
 352                 { "/proc/sys", "/proc/sys", NULL,    NULL,       MS_BIND, true                       },   /* Bind mount first */
 353                 { NULL,        "/proc/sys", NULL,    NULL,       MS_BIND|MS_RDONLY|MS_REMOUNT, true  },   /* Then, make it r/o */
 354                 { "sysfs",     "/sys",      "sysfs", NULL,       MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV, true  },
 355                 { "tmpfs",     "/dev",      "tmpfs", "mode=755", MS_NOSUID|MS_STRICTATIME,     true  },
 356                 { "devpts",    "/dev/pts",  "devpts","newinstance,ptmxmode=0666,mode=620,gid=" STRINGIFY(TTY_GID), MS_NOSUID|MS_NOEXEC, true },
 357                 { "tmpfs",     "/dev/shm",  "tmpfs", "mode=1777", MS_NOSUID|MS_NODEV|MS_STRICTATIME, true  },
 358                 { "tmpfs",     "/run",      "tmpfs", "mode=755", MS_NOSUID|MS_NODEV|MS_STRICTATIME, true  },
 359 #ifdef HAVE_SELINUX
 360                 { "/sys/fs/selinux", "/sys/fs/selinux", NULL, NULL, MS_BIND,                      false },  /* Bind mount first */
 361                 { NULL,              "/sys/fs/selinux", NULL, NULL, MS_BIND|MS_RDONLY|MS_REMOUNT, false },  /* Then, make it r/o */
 362 #endif
 363         };
 364
 365         unsigned k;
 366         int r = 0;
 367
 368         for (k = 0; k < ELEMENTSOF(mount_table); k++) {
 369                 _cleanup_free_ char *where = NULL;
 370                 int t;
 371
 372                 where = strjoin(dest, "/", mount_table[k].where, NULL);
 373                 if (!where)
 374                         return log_oom();
 375
 376                 t = path_is_mount_point(where, true);
 377                 if (t < 0) {
 378                         log_error("Failed to detect whether %s is a mount point: %s", where, strerror(-t));
 379
 380                         if (r == 0)
 381                                 r = t;
 382
 383                         continue;
 384                 }
 385
 386                 /* Skip this entry if it is not a remount. */
 387                 if (mount_table[k].what && t > 0)
 388                         continue;
 389
 390                 mkdir_p(where, 0755);
 391
 392                 if (mount(mount_table[k].what,
 393                           where,
 394                           mount_table[k].type,
 395                           mount_table[k].flags,
 396                           mount_table[k].options) < 0 &&
 397                     mount_table[k].fatal) {
 398
 399                         log_error("mount(%s) failed: %m", where);
 400
 401                         if (r == 0)
 402                                 r = -errno;
 403                 }
 404         }
 405
 406         return r;
 407 }
 408
 409 static int mount_binds(const char *dest, char **l, unsigned long flags) {
 410         char **x, **y;
 411
 412         STRV_FOREACH_PAIR(x, y, l) {
 413                 _cleanup_free_ char *where = NULL;
 414                 struct stat source_st, dest_st;
 415
 416                 if (stat(*x, &source_st) < 0) {
 417                         log_error("failed to stat %s: %m", *x);
 418                         return -errno;
 419                 }
 420
 421                 where = strjoin(dest, "/", *y, NULL);
 422                 if (!where)
 423                         return log_oom();
 424
 425                 if (stat(where, &dest_st) == 0) {
 426                         if ((source_st.st_mode & S_IFMT) != (dest_st.st_mode & S_IFMT)) {
 427                                 log_error("The file types of %s and %s do not match. Refusing bind mount",
 428                                                 *x, where);
 429                                 return -EINVAL;
 430                         }
 431                 } else {
 432                         /* Create the mount point, but be conservative -- refuse to create block
 433                          * and char devices. */
 434                         if (S_ISDIR(source_st.st_mode))
 435                                 mkdir_p_label(where, 0755);
 436                         else if (S_ISFIFO(source_st.st_mode))
 437                                 mkfifo(where, 0644);
 438                         else if (S_ISSOCK(source_st.st_mode))
 439                                 mknod(where, 0644 | S_IFSOCK, 0);
 440                         else if (S_ISREG(source_st.st_mode))
 441                                 touch(where);
 442                         else {
 443                                 log_error("Refusing to create mountpoint for file: %s", *x);
 444                                 return -ENOTSUP;
 445                         }
 446                 }
 447
 448                 if (mount(*x, where, "bind", MS_BIND, NULL) < 0) {
 449                         log_error("mount(%s) failed: %m", where);
 450                         return -errno;
 451                 }
 452
 453                 if (flags && mount(NULL, where, NULL, MS_REMOUNT|MS_BIND|flags, NULL) < 0) {
 454                         log_error("mount(%s) failed: %m", where);
 455                         return -errno;
 456                 }
 457         }
 458
 459         return 0;
 460 }
 461
 462 static int setup_timezone(const char *dest) {
 463         _cleanup_free_ char *where = NULL, *p = NULL, *q = NULL, *check = NULL, *what = NULL;
 464         char *z, *y;
 465         int r;
 466
 467         assert(dest);
 468
 469         /* Fix the timezone, if possible */
 470         r = readlink_malloc("/etc/localtime", &p);
 471         if (r < 0) {
 472                 log_warning("/etc/localtime is not a symlink, not updating container timezone.");
 473                 return 0;
 474         }
 475
 476         z = path_startswith(p, "../usr/share/zoneinfo/");
 477         if (!z)
 478                 z = path_startswith(p, "/usr/share/zoneinfo/");
 479         if (!z) {
 480                 log_warning("/etc/localtime does not point into /usr/share/zoneinfo/, not updating container timezone.");
 481                 return 0;
 482         }
 483
 484         where = strappend(dest, "/etc/localtime");
 485         if (!where)
 486                 return log_oom();
 487
 488         r = readlink_malloc(where, &q);
 489         if (r >= 0) {
 490                 y = path_startswith(q, "../usr/share/zoneinfo/");
 491                 if (!y)
 492                         y = path_startswith(q, "/usr/share/zoneinfo/");
 493
 494
 495                 /* Already pointing to the right place? Then do nothing .. */
 496                 if (y && streq(y, z))
 497                         return 0;
 498         }
 499
 500         check = strjoin(dest, "/usr/share/zoneinfo/", z, NULL);
 501         if (!check)
 502                 return log_oom();
 503
 504         if (access(check, F_OK) < 0) {
 505                 log_warning("Timezone %s does not exist in container, not updating container timezone.", z);
 506                 return 0;
 507         }
 508
 509         what = strappend("../usr/share/zoneinfo/", z);
 510         if (!what)
 511                 return log_oom();
 512
 513         unlink(where);
 514         if (symlink(what, where) < 0) {
 515                 log_error("Failed to correct timezone of container: %m");
 516                 return 0;
 517         }
 518
 519         return 0;
 520 }
 521
 522 static int setup_resolv_conf(const char *dest) {
 523         char _cleanup_free_ *where = NULL;
 524
 525         assert(dest);
 526
 527         if (arg_private_network)
 528                 return 0;
 529
 530         /* Fix resolv.conf, if possible */
 531         where = strappend(dest, "/etc/resolv.conf");
 532         if (!where)
 533                 return log_oom();
 534
 535         /* We don't really care for the results of this really. If it
 536          * fails, it fails, but meh... */
 537         copy_file("/etc/resolv.conf", where, O_TRUNC|O_NOFOLLOW);
 538
 539         return 0;
 540 }
 541
 542 static int setup_boot_id(const char *dest) {
 543         _cleanup_free_ char *from = NULL, *to = NULL;
 544         sd_id128_t rnd;
 545         char as_uuid[37];
 546         int r;
 547
 548         assert(dest);
 549
 550         /* Generate a new randomized boot ID, so that each boot-up of
 551          * the container gets a new one */
 552
 553         from = strappend(dest, "/dev/proc-sys-kernel-random-boot-id");
 554         to = strappend(dest, "/proc/sys/kernel/random/boot_id");
 555         if (!from || !to)
 556                 return log_oom();
 557
 558         r = sd_id128_randomize(&rnd);
 559         if (r < 0) {
 560                 log_error("Failed to generate random boot id: %s", strerror(-r));
 561                 return r;
 562         }
 563
 564         snprintf(as_uuid, sizeof(as_uuid),
 565                  "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
 566                  SD_ID128_FORMAT_VAL(rnd));
 567         char_array_0(as_uuid);
 568
 569         r = write_string_file(from, as_uuid);
 570         if (r < 0) {
 571                 log_error("Failed to write boot id: %s", strerror(-r));
 572                 return r;
 573         }
 574
 575         if (mount(from, to, "bind", MS_BIND, NULL) < 0) {
 576                 log_error("Failed to bind mount boot id: %m");
 577                 r = -errno;
 578         } else if (mount(from, to, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY, NULL))
 579                 log_warning("Failed to make boot id read-only: %m");
 580
 581         unlink(from);
 582         return r;
 583 }
 584
 585 static int copy_devnodes(const char *dest) {
 586
 587         static const char devnodes[] =
 588                 "null\0"
 589                 "zero\0"
 590                 "full\0"
 591                 "random\0"
 592                 "urandom\0"
 593                 "tty\0";
 594
 595         const char *d;
 596         int r = 0;
 597         _cleanup_umask_ mode_t u;
 598
 599         assert(dest);
 600
 601         u = umask(0000);
 602
 603         NULSTR_FOREACH(d, devnodes) {
 604                 struct stat st;
 605                 _cleanup_free_ char *from = NULL, *to = NULL;
 606
 607                 asprintf(&from, "/dev/%s", d);
 608                 asprintf(&to, "%s/dev/%s", dest, d);
 609
 610                 if (!from || !to) {
 611                         log_oom();
 612
 613                         if (r == 0)
 614                                 r = -ENOMEM;
 615
 616                         break;
 617                 }
 618
 619                 if (stat(from, &st) < 0) {
 620
 621                         if (errno != ENOENT) {
 622                                 log_error("Failed to stat %s: %m", from);
 623                                 if (r == 0)
 624                                         r = -errno;
 625                         }
 626
 627                 } else if (!S_ISCHR(st.st_mode) && !S_ISBLK(st.st_mode)) {
 628
 629                         log_error("%s is not a char or block device, cannot copy", from);
 630                         if (r == 0)
 631                                 r = -EIO;
 632
 633                 } else if (mknod(to, st.st_mode, st.st_rdev) < 0) {
 634
 635                         log_error("mknod(%s) failed: %m", dest);
 636                         if (r == 0)
 637                                 r = -errno;
 638                 }
 639         }
 640
 641         return r;
 642 }
 643
 644 static int setup_ptmx(const char *dest) {
 645         _cleanup_free_ char *p = NULL;
 646
 647         p = strappend(dest, "/dev/ptmx");
 648         if (!p)
 649                 return log_oom();
 650
 651         if (symlink("pts/ptmx", p) < 0) {
 652                 log_error("Failed to create /dev/ptmx symlink: %m");
 653                 return -errno;
 654         }
 655
 656         return 0;
 657 }
 658
 659 static int setup_dev_console(const char *dest, const char *console) {
 660         struct stat st;
 661         _cleanup_free_ char *to = NULL;
 662         int r;
 663         _cleanup_umask_ mode_t u;
 664
 665         assert(dest);
 666         assert(console);
 667
 668         u = umask(0000);
 669
 670         if (stat(console, &st) < 0) {
 671                 log_error("Failed to stat %s: %m", console);
 672                 return -errno;
 673
 674         } else if (!S_ISCHR(st.st_mode)) {
 675                 log_error("/dev/console is not a char device");
 676                 return -EIO;
 677         }
 678
 679         r = chmod_and_chown(console, 0600, 0, 0);
 680         if (r < 0) {
 681                 log_error("Failed to correct access mode for TTY: %s", strerror(-r));
 682                 return r;
 683         }
 684
 685         if (asprintf(&to, "%s/dev/console", dest) < 0)
 686                 return log_oom();
 687
 688         /* We need to bind mount the right tty to /dev/console since
 689          * ptys can only exist on pts file systems. To have something
 690          * to bind mount things on we create a device node first, that
 691          * has the right major/minor (note that the major minor
 692          * doesn't actually matter here, since we mount it over
 693          * anyway). */
 694
 695         if (mknod(to, (st.st_mode & ~07777) | 0600, st.st_rdev) < 0) {
 696                 log_error("mknod() for /dev/console failed: %m");
 697                 return -errno;
 698         }
 699
 700         if (mount(console, to, "bind", MS_BIND, NULL) < 0) {
 701                 log_error("Bind mount for /dev/console failed: %m");
 702                 return -errno;
 703         }
 704
 705         return 0;
 706 }
 707
 708 static int setup_kmsg(const char *dest, int kmsg_socket) {
 709         _cleanup_free_ char *from = NULL, *to = NULL;
 710         int r, fd, k;
 711         _cleanup_umask_ mode_t u;
 712         union {
 713                 struct cmsghdr cmsghdr;
 714                 uint8_t buf[CMSG_SPACE(sizeof(int))];
 715         } control = {};
 716         struct msghdr mh = {
 717                 .msg_control = &control,
 718                 .msg_controllen = sizeof(control),
 719         };
 720         struct cmsghdr *cmsg;
 721
 722         assert(dest);
 723         assert(kmsg_socket >= 0);
 724
 725         u = umask(0000);
 726
 727         /* We create the kmsg FIFO as /dev/kmsg, but immediately
 728          * delete it after bind mounting it to /proc/kmsg. While FIFOs
 729          * on the reading side behave very similar to /proc/kmsg,
 730          * their writing side behaves differently from /dev/kmsg in
 731          * that writing blocks when nothing is reading. In order to
 732          * avoid any problems with containers deadlocking due to this
 733          * we simply make /dev/kmsg unavailable to the container. */
 734         if (asprintf(&from, "%s/dev/kmsg", dest) < 0 ||
 735             asprintf(&to, "%s/proc/kmsg", dest) < 0)
 736                 return log_oom();
 737
 738         if (mkfifo(from, 0600) < 0) {
 739                 log_error("mkfifo() for /dev/kmsg failed: %m");
 740                 return -errno;
 741         }
 742
 743         r = chmod_and_chown(from, 0600, 0, 0);
 744         if (r < 0) {
 745                 log_error("Failed to correct access mode for /dev/kmsg: %s", strerror(-r));
 746                 return r;
 747         }
 748
 749         if (mount(from, to, "bind", MS_BIND, NULL) < 0) {
 750                 log_error("Bind mount for /proc/kmsg failed: %m");
 751                 return -errno;
 752         }
 753
 754         fd = open(from, O_RDWR|O_NDELAY|O_CLOEXEC);
 755         if (fd < 0) {
 756                 log_error("Failed to open fifo: %m");
 757                 return -errno;
 758         }
 759
 760         cmsg = CMSG_FIRSTHDR(&mh);
 761         cmsg->cmsg_level = SOL_SOCKET;
 762         cmsg->cmsg_type = SCM_RIGHTS;
 763         cmsg->cmsg_len = CMSG_LEN(sizeof(int));
 764         memcpy(CMSG_DATA(cmsg), &fd, sizeof(int));
 765
 766         mh.msg_controllen = cmsg->cmsg_len;
 767
 768         /* Store away the fd in the socket, so that it stays open as
 769          * long as we run the child */
 770         k = sendmsg(kmsg_socket, &mh, MSG_DONTWAIT|MSG_NOSIGNAL);
 771         close_nointr_nofail(fd);
 772
 773         if (k < 0) {
 774                 log_error("Failed to send FIFO fd: %m");
 775                 return -errno;
 776         }
 777
 778         /* And now make the FIFO unavailable as /dev/kmsg... */
 779         unlink(from);
 780         return 0;
 781 }
 782
 783 static int setup_hostname(void) {
 784
 785         if (sethostname(arg_machine, strlen(arg_machine)) < 0)
 786                 return -errno;
 787
 788         return 0;
 789 }
 790
 791 static int setup_journal(const char *directory) {
 792         sd_id128_t machine_id;
 793         _cleanup_free_ char *p = NULL, *b = NULL, *q = NULL, *d = NULL;
 794         char *id;
 795         int r;
 796
 797         if (arg_link_journal == LINK_NO)
 798                 return 0;
 799
 800         p = strappend(directory, "/etc/machine-id");
 801         if (!p)
 802                 return log_oom();
 803
 804         r = read_one_line_file(p, &b);
 805         if (r == -ENOENT && arg_link_journal == LINK_AUTO)
 806                 return 0;
 807         else if (r < 0) {
 808                 log_error("Failed to read machine ID from %s: %s", p, strerror(-r));
 809                 return r;
 810         }
 811
 812         id = strstrip(b);
 813         if (isempty(id) && arg_link_journal == LINK_AUTO)
 814                 return 0;
 815
 816         /* Verify validity */
 817         r = sd_id128_from_string(id, &machine_id);
 818         if (r < 0) {
 819                 log_error("Failed to parse machine ID from %s: %s", p, strerror(-r));
 820                 return r;
 821         }
 822
 823         free(p);
 824         p = strappend("/var/log/journal/", id);
 825         q = strjoin(directory, "/var/log/journal/", id, NULL);
 826         if (!p || !q)
 827                 return log_oom();
 828
 829         if (path_is_mount_point(p, false) > 0) {
 830                 if (arg_link_journal != LINK_AUTO) {
 831                         log_error("%s: already a mount point, refusing to use for journal", p);
 832                         return -EEXIST;
 833                 }
 834
 835                 return 0;
 836         }
 837
 838         if (path_is_mount_point(q, false) > 0) {
 839                 if (arg_link_journal != LINK_AUTO) {
 840                         log_error("%s: already a mount point, refusing to use for journal", q);
 841                         return -EEXIST;
 842                 }
 843
 844                 return 0;
 845         }
 846
 847         r = readlink_and_make_absolute(p, &d);
 848         if (r >= 0) {
 849                 if ((arg_link_journal == LINK_GUEST ||
 850                      arg_link_journal == LINK_AUTO) &&
 851                     path_equal(d, q)) {
 852
 853                         r = mkdir_p(q, 0755);
 854                         if (r < 0)
 855                                 log_warning("failed to create directory %s: %m", q);
 856                         return 0;
 857                 }
 858
 859                 if (unlink(p) < 0) {
 860                         log_error("Failed to remove symlink %s: %m", p);
 861                         return -errno;
 862                 }
 863         } else if (r == -EINVAL) {
 864
 865                 if (arg_link_journal == LINK_GUEST &&
 866                     rmdir(p) < 0) {
 867
 868                         if (errno == ENOTDIR) {
 869                                 log_error("%s already exists and is neither a symlink nor a directory", p);
 870                                 return r;
 871                         } else {
 872                                 log_error("Failed to remove %s: %m", p);
 873                                 return -errno;
 874                         }
 875                 }
 876         } else if (r != -ENOENT) {
 877                 log_error("readlink(%s) failed: %m", p);
 878                 return r;
 879         }
 880
 881         if (arg_link_journal == LINK_GUEST) {
 882
 883                 if (symlink(q, p) < 0) {
 884                         log_error("Failed to symlink %s to %s: %m", q, p);
 885                         return -errno;
 886                 }
 887
 888                 r = mkdir_p(q, 0755);
 889                 if (r < 0)
 890                         log_warning("failed to create directory %s: %m", q);
 891                 return 0;
 892         }
 893
 894         if (arg_link_journal == LINK_HOST) {
 895                 r = mkdir_p(p, 0755);
 896                 if (r < 0) {
 897                         log_error("Failed to create %s: %m", p);
 898                         return r;
 899                 }
 900
 901         } else if (access(p, F_OK) < 0)
 902                 return 0;
 903
 904         if (dir_is_empty(q) == 0) {
 905                 log_error("%s not empty.", q);
 906                 return -ENOTEMPTY;
 907         }
 908
 909         r = mkdir_p(q, 0755);
 910         if (r < 0) {
 911                 log_error("Failed to create %s: %m", q);
 912                 return r;
 913         }
 914
 915         if (mount(p, q, "bind", MS_BIND, NULL) < 0) {
 916                 log_error("Failed to bind mount journal from host into guest: %m");
 917                 return -errno;
 918         }
 919
 920         return 0;
 921 }
 922
 923 static int drop_capabilities(void) {
 924         return capability_bounding_set_drop(~arg_retain, false);
 925 }
 926
 927 static int register_machine(void) {
 928         _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
 929         _cleanup_bus_unref_ sd_bus *bus = NULL;
 930         int r;
 931
 932         r = sd_bus_open_system(&bus);
 933         if (r < 0) {
 934                 log_error("Failed to open system bus: %s", strerror(-r));
 935                 return r;
 936         }
 937
 938         r = sd_bus_call_method(
 939                         bus,
 940                         "org.freedesktop.machine1",
 941                         "/org/freedesktop/machine1",
 942                         "org.freedesktop.machine1.Manager",
 943                         "CreateMachine",
 944                         &error,
 945                         NULL,
 946                         "sayssusa(sv)",
 947                         arg_machine,
 948                         SD_BUS_MESSAGE_APPEND_ID128(arg_uuid),
 949                         "nspawn",
 950                         "container",
 951                         (uint32_t) 0,
 952                         strempty(arg_directory),
 953                         !isempty(arg_slice), "Slice", "s", arg_slice);
 954         if (r < 0) {
 955                 log_error("Failed to register machine: %s", error.message ? error.message : strerror(-r));
 956                 return r;
 957         }
 958
 959         return 0;
 960 }
 961
 962 static bool audit_enabled(void) {
 963         int fd;
 964
 965         fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_AUDIT);
 966         if (fd >= 0) {
 967                 close_nointr_nofail(fd);
 968                 return true;
 969         }
 970         return false;
 971 }
 972
 973 int main(int argc, char *argv[]) {
 974         pid_t pid = 0;
 975         int r = EXIT_FAILURE, k;
 976         _cleanup_close_ int master = -1;
 977         int n_fd_passed;
 978         const char *console = NULL;
 979         sigset_t mask;
 980         _cleanup_close_pipe_ int kmsg_socket_pair[2] = { -1, -1 };
 981         _cleanup_fdset_free_ FDSet *fds = NULL;
 982
 983         log_parse_environment();
 984         log_open();
 985
 986         k = parse_argv(argc, argv);
 987         if (k < 0)
 988                 goto finish;
 989         else if (k == 0) {
 990                 r = EXIT_SUCCESS;
 991                 goto finish;
 992         }
 993
 994         if (arg_directory) {
 995                 char *p;
 996
 997                 p = path_make_absolute_cwd(arg_directory);
 998                 free(arg_directory);
 999                 arg_directory = p;
1000         } else
1001                 arg_directory = get_current_dir_name();
1002
1003         if (!arg_directory) {
1004                 log_error("Failed to determine path, please use -D.");
1005                 goto finish;
1006         }
1007
1008         path_kill_slashes(arg_directory);
1009
1010         if (!arg_machine) {
1011                 arg_machine = strdup(path_get_file_name(arg_directory));
1012                 if (!arg_machine) {
1013                         log_oom();
1014                         goto finish;
1015                 }
1016
1017                 hostname_cleanup(arg_machine, false);
1018                 if (isempty(arg_machine)) {
1019                         log_error("Failed to determine machine name automatically, please use -M.");
1020                         goto finish;
1021                 }
1022         }
1023
1024         if (geteuid() != 0) {
1025                 log_error("Need to be root.");
1026                 goto finish;
1027         }
1028
1029         if (sd_booted() <= 0) {
1030                 log_error("Not running on a systemd system.");
1031                 goto finish;
1032         }
1033
1034         if (arg_boot && audit_enabled()) {
1035                 log_warning("The kernel auditing subsystem is known to be incompatible with containers.\n"
1036                             "Please make sure to turn off auditing with 'audit=0' on the kernel command\n"
1037                             "line before using systemd-nspawn. Sleeping for 5s...\n");
1038                 sleep(5);
1039         }
1040
1041         if (path_equal(arg_directory, "/")) {
1042                 log_error("Spawning container on root directory not supported.");
1043                 goto finish;
1044         }
1045
1046         if (path_is_os_tree(arg_directory) <= 0) {
1047                 log_error("Directory %s doesn't look like an OS root directory (/etc/os-release is missing). Refusing.", arg_directory);
1048                 goto finish;
1049         }
1050
1051         log_close();
1052         n_fd_passed = sd_listen_fds(false);
1053         if (n_fd_passed > 0) {
1054                 k = fdset_new_listen_fds(&fds, false);
1055                 if (k < 0) {
1056                         log_error("Failed to collect file descriptors: %s", strerror(-k));
1057                         goto finish;
1058                 }
1059         }
1060         fdset_close_others(fds);
1061         log_open();
1062
1063         master = posix_openpt(O_RDWR|O_NOCTTY|O_CLOEXEC|O_NDELAY);
1064         if (master < 0) {
1065                 log_error("Failed to acquire pseudo tty: %m");
1066                 goto finish;
1067         }
1068
1069         console = ptsname(master);
1070         if (!console) {
1071                 log_error("Failed to determine tty name: %m");
1072                 goto finish;
1073         }
1074
1075         log_info("Spawning container %s on %s. Press ^] three times within 1s to abort execution.", arg_machine, arg_directory);
1076
1077         if (unlockpt(master) < 0) {
1078                 log_error("Failed to unlock tty: %m");
1079                 goto finish;
1080         }
1081
1082         if (socketpair(AF_UNIX, SOCK_DGRAM|SOCK_NONBLOCK|SOCK_CLOEXEC, 0, kmsg_socket_pair) < 0) {
1083                 log_error("Failed to create kmsg socket pair.");
1084                 goto finish;
1085         }
1086
1087         sd_notify(0, "READY=1");
1088
1089         assert_se(sigemptyset(&mask) == 0);
1090         sigset_add_many(&mask, SIGCHLD, SIGWINCH, SIGTERM, SIGINT, -1);
1091         assert_se(sigprocmask(SIG_BLOCK, &mask, NULL) == 0);
1092
1093         for (;;) {
1094                 siginfo_t status;
1095
1096                 pid = syscall(__NR_clone, SIGCHLD|CLONE_NEWIPC|CLONE_NEWNS|CLONE_NEWPID|CLONE_NEWUTS|(arg_private_network ? CLONE_NEWNET : 0), NULL);
1097                 if (pid < 0) {
1098                         if (errno == EINVAL)
1099                                 log_error("clone() failed, do you have namespace support enabled in your kernel? (You need UTS, IPC, PID and NET namespacing built in): %m");
1100                         else
1101                                 log_error("clone() failed: %m");
1102
1103                         goto finish;
1104                 }
1105
1106                 if (pid == 0) {
1107                         /* child */
1108                         const char *home = NULL;
1109                         uid_t uid = (uid_t) -1;
1110                         gid_t gid = (gid_t) -1;
1111                         unsigned n_env = 2;
1112                         const char *envp[] = {
1113                                 "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
1114                                 "container=systemd-nspawn", /* LXC sets container=lxc, so follow the scheme here */
1115                                 NULL, /* TERM */
1116                                 NULL, /* HOME */
1117                                 NULL, /* USER */
1118                                 NULL, /* LOGNAME */
1119                                 NULL, /* container_uuid */
1120                                 NULL, /* LISTEN_FDS */
1121                                 NULL, /* LISTEN_PID */
1122                                 NULL
1123                         };
1124
1125                         envp[n_env] = strv_find_prefix(environ, "TERM=");
1126                         if (envp[n_env])
1127                                 n_env ++;
1128
1129                         close_nointr_nofail(master);
1130                         master = -1;
1131
1132                         close_nointr(STDIN_FILENO);
1133                         close_nointr(STDOUT_FILENO);
1134                         close_nointr(STDERR_FILENO);
1135
1136                         close_nointr_nofail(kmsg_socket_pair[0]);
1137                         kmsg_socket_pair[0] = -1;
1138
1139                         reset_all_signal_handlers();
1140
1141                         assert_se(sigemptyset(&mask) == 0);
1142                         assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
1143
1144                         k = open_terminal(console, O_RDWR);
1145                         if (k != STDIN_FILENO) {
1146                                 if (k >= 0) {
1147                                         close_nointr_nofail(k);
1148                                         k = -EINVAL;
1149                                 }
1150
1151                                 log_error("Failed to open console: %s", strerror(-k));
1152                                 goto child_fail;
1153                         }
1154
1155                         if (dup2(STDIN_FILENO, STDOUT_FILENO) != STDOUT_FILENO ||
1156                             dup2(STDIN_FILENO, STDERR_FILENO) != STDERR_FILENO) {
1157                                 log_error("Failed to duplicate console: %m");
1158                                 goto child_fail;
1159                         }
1160
1161                         if (setsid() < 0) {
1162                                 log_error("setsid() failed: %m");
1163                                 goto child_fail;
1164                         }
1165
1166                         if (prctl(PR_SET_PDEATHSIG, SIGKILL) < 0) {
1167                                 log_error("PR_SET_PDEATHSIG failed: %m");
1168                                 goto child_fail;
1169                         }
1170
1171                         r = register_machine();
1172                         if (r < 0)
1173                                 goto finish;
1174
1175                         /* Mark everything as slave, so that we still
1176                          * receive mounts from the real root, but don't
1177                          * propagate mounts to the real root. */
1178                         if (mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL) < 0) {
1179                                 log_error("MS_SLAVE|MS_REC failed: %m");
1180                                 goto child_fail;
1181                         }
1182
1183                         /* Turn directory into bind mount */
1184                         if (mount(arg_directory, arg_directory, "bind", MS_BIND|MS_REC, NULL) < 0) {
1185                                 log_error("Failed to make bind mount.");
1186                                 goto child_fail;
1187                         }
1188
1189                         if (arg_read_only)
1190                                 if (mount(arg_directory, arg_directory, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY|MS_REC, NULL) < 0) {
1191                                         log_error("Failed to make read-only.");
1192                                         goto child_fail;
1193                                 }
1194
1195                         if (mount_all(arg_directory) < 0)
1196                                 goto child_fail;
1197
1198                         if (copy_devnodes(arg_directory) < 0)
1199                                 goto child_fail;
1200
1201                         if (setup_ptmx(arg_directory) < 0)
1202                                 goto child_fail;
1203
1204                         dev_setup(arg_directory);
1205
1206                         if (setup_dev_console(arg_directory, console) < 0)
1207                                 goto child_fail;
1208
1209                         if (setup_kmsg(arg_directory, kmsg_socket_pair[1]) < 0)
1210                                 goto child_fail;
1211
1212                         close_nointr_nofail(kmsg_socket_pair[1]);
1213                         kmsg_socket_pair[1] = -1;
1214
1215                         if (setup_boot_id(arg_directory) < 0)
1216                                 goto child_fail;
1217
1218                         if (setup_timezone(arg_directory) < 0)
1219                                 goto child_fail;
1220
1221                         if (setup_resolv_conf(arg_directory) < 0)
1222                                 goto child_fail;
1223
1224                         if (setup_journal(arg_directory) < 0)
1225                                 goto child_fail;
1226
1227                         if (mount_binds(arg_directory, arg_bind, 0) < 0)
1228                                 goto child_fail;
1229
1230                         if (mount_binds(arg_directory, arg_bind_ro, MS_RDONLY) < 0)
1231                                 goto child_fail;
1232
1233                         if (chdir(arg_directory) < 0) {
1234                                 log_error("chdir(%s) failed: %m", arg_directory);
1235                                 goto child_fail;
1236                         }
1237
1238                         if (mount(arg_directory, "/", NULL, MS_MOVE, NULL) < 0) {
1239                                 log_error("mount(MS_MOVE) failed: %m");
1240                                 goto child_fail;
1241                         }
1242
1243                         if (chroot(".") < 0) {
1244                                 log_error("chroot() failed: %m");
1245                                 goto child_fail;
1246                         }
1247
1248                         if (chdir("/") < 0) {
1249                                 log_error("chdir() failed: %m");
1250                                 goto child_fail;
1251                         }
1252
1253                         umask(0022);
1254
1255                         loopback_setup();
1256
1257                         if (drop_capabilities() < 0) {
1258                                 log_error("drop_capabilities() failed: %m");
1259                                 goto child_fail;
1260                         }
1261
1262                         if (arg_user) {
1263
1264                                 /* Note that this resolves user names
1265                                  * inside the container, and hence
1266                                  * accesses the NSS modules from the
1267                                  * container and not the host. This is
1268                                  * a bit weird... */
1269
1270                                 if (get_user_creds((const char**)&arg_user, &uid, &gid, &home, NULL) < 0) {
1271                                         log_error("get_user_creds() failed: %m");
1272                                         goto child_fail;
1273                                 }
1274
1275                                 if (mkdir_parents_label(home, 0775) < 0) {
1276                                         log_error("mkdir_parents_label() failed: %m");
1277                                         goto child_fail;
1278                                 }
1279
1280                                 if (mkdir_safe_label(home, 0775, uid, gid) < 0) {
1281                                         log_error("mkdir_safe_label() failed: %m");
1282                                         goto child_fail;
1283                                 }
1284
1285                                 if (initgroups((const char*)arg_user, gid) < 0) {
1286                                         log_error("initgroups() failed: %m");
1287                                         goto child_fail;
1288                                 }
1289
1290                                 if (setresgid(gid, gid, gid) < 0) {
1291                                         log_error("setregid() failed: %m");
1292                                         goto child_fail;
1293                                 }
1294
1295                                 if (setresuid(uid, uid, uid) < 0) {
1296                                         log_error("setreuid() failed: %m");
1297                                         goto child_fail;
1298                                 }
1299                         } else {
1300                                 /* Reset everything fully to 0, just in case */
1301
1302                                 if (setgroups(0, NULL) < 0) {
1303                                         log_error("setgroups() failed: %m");
1304                                         goto child_fail;
1305                                 }
1306
1307                                 if (setresgid(0, 0, 0) < 0) {
1308                                         log_error("setregid() failed: %m");
1309                                         goto child_fail;
1310                                 }
1311
1312                                 if (setresuid(0, 0, 0) < 0) {
1313                                         log_error("setreuid() failed: %m");
1314                                         goto child_fail;
1315                                 }
1316                         }
1317
1318                         if ((asprintf((char**)(envp + n_env++), "HOME=%s", home ? home: "/root") < 0) ||
1319                             (asprintf((char**)(envp + n_env++), "USER=%s", arg_user ? arg_user : "root") < 0) ||
1320                             (asprintf((char**)(envp + n_env++), "LOGNAME=%s", arg_user ? arg_user : "root") < 0)) {
1321                                 log_oom();
1322                                 goto child_fail;
1323                         }
1324
1325                         if (!sd_id128_equal(arg_uuid, SD_ID128_NULL)) {
1326                                 if (asprintf((char**)(envp + n_env++), "container_uuid=" SD_ID128_FORMAT_STR, SD_ID128_FORMAT_VAL(arg_uuid)) < 0) {
1327                                         log_oom();
1328                                         goto child_fail;
1329                                 }
1330                         }
1331
1332                         if (fdset_size(fds) > 0) {
1333                                 k = fdset_cloexec(fds, false);
1334                                 if (k < 0) {
1335                                         log_error("Failed to unset O_CLOEXEC for file descriptors.");
1336                                         goto child_fail;
1337                                 }
1338
1339                                 if ((asprintf((char **)(envp + n_env++), "LISTEN_FDS=%u", n_fd_passed) < 0) ||
1340                                     (asprintf((char **)(envp + n_env++), "LISTEN_PID=1") < 0)) {
1341                                         log_oom();
1342                                         goto child_fail;
1343                                 }
1344                         }
1345
1346                         setup_hostname();
1347
1348                         if (arg_boot) {
1349                                 char **a;
1350                                 size_t l;
1351
1352                                 /* Automatically search for the init system */
1353
1354                                 l = 1 + argc - optind;
1355                                 a = newa(char*, l + 1);
1356                                 memcpy(a + 1, argv + optind, l * sizeof(char*));
1357
1358                                 a[0] = (char*) "/usr/lib/systemd/systemd";
1359                                 execve(a[0], a, (char**) envp);
1360
1361                                 a[0] = (char*) "/lib/systemd/systemd";
1362                                 execve(a[0], a, (char**) envp);
1363
1364                                 a[0] = (char*) "/sbin/init";
1365                                 execve(a[0], a, (char**) envp);
1366                         } else if (argc > optind)
1367                                 execvpe(argv[optind], argv + optind, (char**) envp);
1368                         else {
1369                                 chdir(home ? home : "/root");
1370                                 execle("/bin/bash", "-bash", NULL, (char**) envp);
1371                         }
1372
1373                         log_error("execv() failed: %m");
1374
1375                 child_fail:
1376                         _exit(EXIT_FAILURE);
1377                 }
1378
1379                 fdset_free(fds);
1380                 fds = NULL;
1381
1382                 k = process_pty(master, &mask, arg_boot ? pid : 0, SIGRTMIN+3);
1383                 if (k < 0) {
1384                         r = EXIT_FAILURE;
1385                         break;
1386                 }
1387
1388                 putc('\n', stdout);
1389
1390                 /* Kill if it is not dead yet anyway */
1391                 kill(pid, SIGKILL);
1392
1393                 k = wait_for_terminate(pid, &status);
1394                 pid = 0;
1395
1396                 if (k < 0) {
1397                         r = EXIT_FAILURE;
1398                         break;
1399                 }
1400
1401                 if (status.si_code == CLD_EXITED) {
1402                         r = status.si_status;
1403                         if (status.si_status != 0) {
1404                                 log_error("Container %s failed with error code %i.", arg_machine, status.si_status);
1405                                 break;
1406                         }
1407
1408                         log_debug("Container %s exited successfully.", arg_machine);
1409                         break;
1410                 } else if (status.si_code == CLD_KILLED &&
1411                            status.si_status == SIGINT) {
1412                         log_info("Container %s has been shut down.", arg_machine);
1413                         r = 0;
1414                         break;
1415                 } else if (status.si_code == CLD_KILLED &&
1416                            status.si_status == SIGHUP) {
1417                         log_info("Container %s is being rebooted.", arg_machine);
1418                         continue;
1419                 } else if (status.si_code == CLD_KILLED ||
1420                            status.si_code == CLD_DUMPED) {
1421
1422                         log_error("Container %s terminated by signal %s.", arg_machine,  signal_to_string(status.si_status));
1423                         r = EXIT_FAILURE;
1424                         break;
1425                 } else {
1426                         log_error("Container %s failed due to unknown reason.", arg_machine);
1427                         r = EXIT_FAILURE;
1428                         break;
1429                 }
1430         }
1431
1432 finish:
1433         if (pid > 0)
1434                 kill(pid, SIGKILL);
1435
1436         free(arg_directory);
1437         free(arg_machine);
1438
1439         return r;
1440 }